It is already known to mount supplementary decks between the existing decks in ships in order to make better use of the available space in ship hulls for transport of goods of the kind that is not readily stackable, such as e.g. cars. Such supplementary decks must be easy to erect and dismantle, according to need.
The purpose of the subject invention is precisely to provide an arrangement according to which supplementary decks may be conveniently mounted between the existing decks in ships of the kind which are built to carry loading containers and wherein in the existing decks are formed apertures, arranged in groups of four, which aperture groups are distributed over the deck equally pitched to receive locking bolts of the kind known as twist locks which serve to removably secure the loading containers to the deck.